Biped locomotion robot

ABSTRACT

The movement analysis becomes easy and the control of all the movement systems is realized better through the initialization of the multiple coordinate systems. The fundamental body portion  6  is coupled to a foot portion  5  through a first joint portion  7 , a first link  3 , a second joint portion  8 , a second link  4 , and a third joint portion  9 . The rigidity of the first link  3  is lower than that of the fundamental body portion  6 , and the rigidity of the second link  4  is lower than that of the second link  4 . It is possible to position the second link  4  and the foot portion  5  in a high precision to a mechanical origin which is predetermined to the fundamental body portion, for the reason of the rigidity relation. Handle portions  13  are coupled in two positions to the fundamental body portion  6 . When the whole posture is initialized based on the mechanical origin, the center of gravity G of the whole robot is located between two vertical planes containing the two positions. In the initialization, a first joint portion  7 , a second joint portion  8 , and a third joint portion  9  are located between the two vertical planes. Thus, because the whole balance is taken, the origin adjustment is easy.

TECHNICAL FIELD

[0001] The present invention relates to a biped locomotion robot.

BACKGROUND ART

[0002] A humanoid robot, especially a biped locomotion robot has beingdeveloped as an autonomous movement machine operable in environments forthe human beings to execute difficult activities such as care activityin home and rescue activity in a fire scene instead of the human beings.As shown in FIG. 1, such a robot is composed of an element system of aplurality of elements (head 101, body 102, and legs 103) which are undersubordinative control each other based on multiple joints, and anelement relating system which relates the element system (joints 104,105, 106, 107, 108, and 109 as 1-, 2- and 3-axis rotation systems). Thewhole control of the element system of the plurality of elements and theelement relating system is described based on multiple variablesbelonging to each system and multiple parameters. However, it isdifficult to separate independence and subordination between themultiple variables in a high precision in the development phaseactually. Also, it is difficult to describe a foot rising movement and afoot grounding movement on walking correctly.

[0003] When a theoretical walking movement and an actual walkingmovement do not coincide with each other, it would be analyzed that thecause of the discrepancy depends on which of the variables. However,mechanical elements of the plurality of elements have physicalparameters, and especially the rigidity and mass of each mechanicalelement have an important influence on the walking movement. For thisreason, it is difficult to theoretically analyze whether the instabilityof control depends on the mass of the head or the rigidity of the bodyor leg. Much more, when each mechanical element is not manufacturedaccording to theory, the analysis is difficult especially.

[0004] Therefore, it is important to design a biped locomotion robotsuch that the changeable ranges of the parameters of all the elementsare restricted in consideration of physical characteristics between theelements in advance, for the purpose of facilitating the analysis andconfirming the quality of the design. Especially, it is important tocause effective attenuation of influence between composite rotationsystems. The definition of reasonable rules about the adjustment andinitialization of a mechanical origin defining an initial condition ofthe movement is more important to prove the quality of the design.

DISCLOSURE OF INVENTION

[0005] An object of the present invention is to provide aself-controlled biped locomotion robot with a small size.

[0006] Another object of the present invention is to provide a bipedlocomotion robot in which movement analysis is easy.

[0007] Another object of the present invention is to provide a bipedlocomotion robot in which the initialization of composite coordinatesystems is easy.

[0008] Another object of the present invention is to provide a bipedlocomotion robot in which the control of the whole movement system canbe realized better.

[0009] In an aspect of the present invention, a biped locomotion robotis composed of a fundamental body portion, an upper body housing rigidlycoupled to the fundamental body portion, two leg portions movablycoupled to the fundamental body portion, a foot portion movably coupledto each of the two leg portions, a head portion movably coupled to theupper body housing, and two arm portions movably coupled to the upperbody housing. It is desirable that the fundamental body portionfunctions as a mechanical origin.

[0010] The biped locomotion robot may be further composed of two handleportions provided for opposing attachment sections of the fundamentalbody portion. Thus, the workability and custody can be improved.

[0011] Also, the center of gravity of the biped locomotion robot isdesirably located between vertical planes, each of which passescorresponding ends of the attachment sections of the handle portions tothe fundamental body portion, when the biped locomotion robot is in aninitial state.

[0012] Also, each of the two leg portions may be composed of a firstlink functioning to support the fundamental body portion through a firstjoint portion and a second link functioning to support the first linkthrough a second joint portion. In this case, it is preferable that ahorizontal rotation axis of the first joint portion and a horizontalrotation axis of the second joint portion are located between thevertical planes, each of passes through corresponding ends of theattachment sections of the two handle portions to the fundamental bodyportion, when the biped locomotion robot is in the initial state.Moreover, each of the foot portions may support a corresponding one ofthe second links through a third joint portion. It is preferable that ahorizontal rotation axis of the third joint portion is located betweenvertical planes, each of which passes through the corresponding ends ofthe attachment sections of the two handle portions to the fundamentalbody portion, when the biped locomotion robot is in the initial state.

[0013] Also, when each of the two leg portions is composed of a firstlink provided to support the fundamental body portion through a firstjoint portion, and a second link provided to support the first linkthrough a second joint portion, it is preferable that the rigidity ofthe first link is lower than that of the fundamental body portion, andthe rigidity of the second link is lower than that of the first link. Itis preferable that the first joint portion has a vertical rotation axis.

[0014] Also, it is desirable that the first joint portion has a verticalrotation axis.

[0015] Also, it is desirable that the upper body housing is coupled tothe fundamental body portion to provide a gap region between the upperbody housing and the fundamental body portion, and an energy source isarranged in the gap region.

[0016] Also, the biped locomotion robot may further include a controlunit provided for a back of the upper body housing.

[0017] Also, in another aspect of the present invention, a bipedlocomotion robot is composed of a fundamental body portion, two firstlinks to support the fundamental body portion through a first jointportion, and a second link to support a corresponding one of the firstlinks through a second joint portion. The rigidity of the first link islower than that of the fundamental body portion and the rigidity of thesecond link is lower than that of the first link. Also, the bipedlocomotion robot is further composed of a foot portion to support acorresponding one of the second links through a third joint portion.Mechanical stress transferred instantaneously through a double pendulumsystem (3, 4, 7, 8) between the fundamental body portion and the footportion is relaxed or damped on the grounding of the foot portion. Thus,the control of mechanical origin for a control system of the fundamentalbody portion becomes easy. As a result, it becomes easy to position thesecond link. Moreover, the positioning of the foot portion attached tothe second link with the minimum rigidity becomes easy.

[0018] In another aspect of the present invention, the biped locomotionrobot is composed of a fundamental body portion in which a mechanicalorigin is set, a first link to support the fundamental body portionthrough a first joint portion, a second link to support the first linkthrough a second joint portion, and a third link to support the secondlink through a third joint portion. The fundamental body portion hashandle portions, and the handle portions are coupled to the fundamentalbody portion at two positions. It is desirable that the center ofgravity (G) of the robot is located between two vertical planes passingthrough the two positions in the initialization of the whole posturewith respect to the mechanical origin. As a result, the rotation momentwhen the whole of robot is carried is small, so that the stability ofthe robot is high and the carrying of the robot is easy. In case of theinitialization, it is desirable that the rotation axis of the firstjoint portion, the rotation axis of the second joint portion, and therotation axis of the third joint portion are located between the twovertical planes. Especially, the two positions corresponding to the twovertical planes are determined as two separate positions in a frontdirection in case of the initialization. It is desirable that the handleportions form a reference plane to the mechanical origin in case of theinitialization, and the grounding surface of the foot portion can beadjusted based on the reference surface of the handle portion.Especially, by adjusting the foot portions such that the referencesurface of the handle portions is parallel to the grounding surfaces ofthe foot portions, the adjustment of the foot portions to the originpoint becomes easy. The handle portions may be outside an exterior bodysuch as a body section cover and may be exposed. Thus, the regularinitialization work becomes easy.

[0019] In another aspect of the present invention, the biped locomotionrobot is composed of a fundamental body portion, an upper body housingsupported by the fundamental body portion, first links to respectivelysupport the fundamental body portion through first joint portions,second links to respectively support the first links through secondjoint portions, foot portions to respectively support the second linksthrough third joint portions, and an upper portion supported by theupper body housing through a fourth joint portion. The upper bodyhousing is attached to the fundamental body portion with a highrigidity, and arm portions and a head portion are supported by the upperbody housing through joint portions. In this way, the rigidity of thesupport structure to support the head portion and the arm portions canbe maintained high. The upper body housing is supported by thefundamental body portion through side plate sections to form a gapregion, and an energy source (cell battery and so on) is arranged in thegap region. Thus, the use efficiency of the space is high.

[0020] Many various holes and an attachment structure are provided forthe fundamental body portion for attachment of the upper portion and thelower portion. Therefore, the fundamental body portion is formed ofthick light alloy as a whole. A proper reinforcement structure may beused for the fundamental body portion.

BRIEF DESCRIPTION OF DRAWINGS

[0021]FIG. 1 is a perspective view showing a conventional bipedlocomotion robot;

[0022]FIG. 2 is a perspective view showing a portion of a bipedlocomotion robot according to an embodiment of the present invention;

[0023]FIG. 3 is a side view geometrically showing a leg portion of therobot shown in FIG. 2;

[0024]FIG. 4 is a perspective view showing an upper body housing;

[0025]FIG. 5 is a perspective view showing an upper body housing with acover;

[0026]FIG. 6 is a side view of the biped locomotion robot shown in FIG.2;

[0027]FIG. 7 is a front view showing a part of the biped locomotionrobot shown in FIG. 2;

[0028]FIG. 8 is a perspective view showing an arm portion, a bodysection, and a head portion;

[0029]FIG. 9 is a front view showing a method of adjusting a mechanicalorigin in the biped locomotion robot according to the embodiment of thepresent invention;

[0030]FIG. 10 is a perspective view geometrically showing a handleportion;

[0031]FIG. 11A is a perspective view showing the method of adjusting themechanical origin in the biped locomotion robot according to theembodiment of the present invention, and FIG. 11B is a diagramgeometrically showing the method of adjusting the mechanical origin;

[0032]FIG. 12 is a perspective view showing a body portion with thecover, in which a power supply section is installed;

[0033]FIG. 13 is a perspective view showing the body portion of thebiped locomotion robot according to the embodiment of the presentinvention;

[0034]FIG. 14 is a perspective view showing the fundamental bodyportion;

[0035]FIG. 15 is a side expanded view showing the leg portion; and

[0036]FIG. 16 is a plan view of the fundamental body portion shown inFIG. 14.

BEST MODE FOR CARRYING OUT THE INVENTION

[0037] Hereinafter, a biped locomotion robot of the present inventionwill be described in detail with reference to the attached drawings.

[0038]FIG. 2 is a perspective view of the biped locomotion robotaccording to an embodiment of the present invention. Referring to FIG.2, the biped locomotion robot of the present invention is composed of afundamental body portion 6, and a body section 1 and two leg portions 2with respect to the fundamental body portion 6. A control unit 26 isprovided on the rear side of the body section 2. In FIG. 2, only one legportion is shown.

[0039] Referring to FIG. 3, the fundamental body portion 6 is a highrigid body. The fundamental body portion 6 is supported 2-axis rotatablyby each of the leg portions 2. Each leg portion 2 is supported 2-axisrotatably by a foot portion 5. Also, the fundamental body portion 6 isprovided with two side plate sections 12 (not shown in FIG. 3) for a gapto stand up in both side ends of the fundamental body portion 6, asshown in FIG. 4.

[0040] Each leg portion 2 has a first leg portion 3 or first link 3 anda second leg portion 4 or second link 4. The first leg portion 3 orfirst link 3 is coupled to the fundamental body portion 6 through a2-axis rotatable first joint portion 7. The second leg portion 4 orsecond link 4 is coupled to the first leg portion 3 through a 1-axisrotatable second joint portion 8. The foot portion 5 is coupled to thesecond leg portion 4 through a 2-axis rotatable third joint portion 9.The foot portion 5 partially has a flat foot back surface contacting aflat floor or flat ground. It should be noted that in this example, theleg portion 2 and the foot portion 5 are coupled 2-axis rotatably.However, the leg portion 2 and the foot portion 5 may be coupled 1-axisrotatably.

[0041] In this way, the second leg portion 4 is supported by the footportion 5 through the third joint portion 9, and the first leg portion 3is supported by the second leg portion 4 through the second jointportion 8. Moreover, the fundamental body portion 6 is supported by thefirst leg portions 3 through the first joint portions 7.

[0042] As shown in FIG. 4, the body section 1 has an upper body housing11. The upper body housing 11 is formed of light alloy as a unit. Theupper body housing 11 has a proper thickness and is formed to have ahigh rigidity. The upper body housing 11 is rigidly coupled to thefundamental body portion 6 with the side plate sections 12 for the gapand is supported by the fundamental body portion 6. The upper bodyhousing 11 is separated from an upper portion of the fundamental bodyportion 6 in an upper vertical direction by the side plate sections 12.A battery cell case 17 is detachably provided in the gap region formedbetween the upper portion of the fundamental body portion 6 and thelower portion of the upper body housing 11.

[0043] As shown in FIG. 4, the upper body housing 11 has a headattachment hole 19 in the upper portion 18. Also, the upper body housing11 has arm attachment holes 23 and 24 in the side portions 11.

[0044] Two handle portions 13 are provided for attachment portionscorresponding to the side plate sections 12 on both sides of thefundamental body portion 6. In more detail, the two handle portions 13are firmly attached to attachment portions 14 on the both side edges ofthe fundamental body portion 6 to oppose to each other. Each of the twohandle portions 13 is attached to the attachment portion 14 at twopositions P and Q. It is preferable that the two corresponding positionsP and the two corresponding positions Q are located on a same plane.Also, it is desirable that the plane is parallel to a horizontal plane,namely, is orthogonal to a vertical axis. Especially, it is desirablethat the two positions P and Q are located on a reference plane whichpasses a mechanical origin to be described later. As shown in FIG. 3, itis desirable that the center of gravity G of the total mass when thebiped locomotion robot is complete is positioned on a vertical planewhich passes a middle point of the two positions P and a middle point ofthe two positions Q, or in the neighborhood of the vertical plane.

[0045] As shown in FIG. 5, the fundamental body portion 6 and the upperbody housing 11 are covered by a body section cover 16. FIG. 6 and FIG.7 show the whole biped locomotion robot when the body section cover 16is attached to the fundamental body portion 6 in this way. In this case,only one leg portion 2 is shown in FIG. 7. The handle portion 13 isexposed outside the body section cover 16. The body section cover 16 hasopenings corresponding to the head attachment hole 19 and arm attachmentholes 23 and 24 in the upper body housing 11.

[0046] As shown in FIG. 8, the head portion 22 is attached to the upperbody housing 11 such that the head portion 22 is adjusted in axis to thehead attachment hole 19 of the upper body housing 11 through the bodysection cover 16 and is supported in the vertical direction. Like thehead portion 2, the arm portions 25 are adjusted in axis to the armattachment holes 23 and 24 of the upper body housing 11 through the bodysection cover 16, and is attached to the upper body housing 11 2-axisrotatably. That is, as shown in FIG. 8, the arm portion 25 has thedegrees of freedom in multiple axes and is attached to the upper bodyhousing 11 freely in swing and turning. The carrying type control unit26 is arranged on the back side of the body section cover 16 and isattached to the fundamental body portion 6, as shown in FIG. 2.

[0047]FIG. 9 shows a method of adjusting a mechanical origin. An elementsystem is composed of a fundamental body portion system S1, first linksystems S2, second link systems S3 and foot systems S4. The state shownin the figure is when a walking examination is carried out with an armsystem omitted. The first link system S2, the second link system S3 andthe foot system S4 are provided for either side but are treated as asingle system.

[0048] As shown in FIG. 10, the handle portion 13 has a unitary body oftransverse bar portions 13A extending in transverse directions and abridge portion 13B extending in a front direction. The surface of thebridge portion 13B, especially, the lower surface of the bridge portion13B is formed as the reference surface SS1 for the mechanical origin. Areference surface SS2 corresponding to the reference surface SS1 for themechanical origin on either side is formed as the upper surface of arigid body pillar 31 which stands up from a reference horizontal floorsurface SS3. The coincidence of the reference surface SS1 for themechanical origin and the reference surface SS2 may be detected by atouch sensor (not shown) which detects contact of the rigid body pillar31 and the handle portion 13.

[0049] The biped locomotion robot has a weight to the extent for a humanbeing, and is carried by using the handle portions 13 on both sides suchthat the reference surface SS1 for the mechanical origin is made tocoincide with the reference surface SS2 of the two rigid pillars 31. Or,the biped locomotion robot is operated by a remote radio control suchthat the reference surface SS1 for the mechanical origin is made tocoincide with the reference surface SS2 of the two rigid pillars. Afterthat, the three coordinate systems S2, S3, and S4 are initialized usingthe coordinate system S1 as reference. That is, in the initial state,the element system is reset to the origins of all the coordinate systemsS1, S2, S3, S4.

[0050]FIGS. 11A and 11B show an allowable range of the mechanicalorigin. The space formed between a vertical plane 32 containing bothpoints P and P of the handle portions 13 on both sides and a verticalplane 33 containing both points Q and Q of the handle portions 13 onboth sides is defined as the allowable range. The control target is thatthe horizontal rotation axis 10 extending in a horizontal direction inthe first joint portion 7, the horizontal rotation axis 8H extending ina horizontal direction in the second joint portion 8, and the horizontalrotation axis 9H extending in a horizontal direction in the third jointportion are located between the two vertical planes 32 and 33. It is notnecessary that the horizontal rotation axes 7H, 8H and 9H are located ona single vertical plane. Rather, it leads excellent stability that thehorizontal rotation axes 7H, 8H and 9H are not located on the singlevertical plane. The whole mass distribution in the robot is designedsuch that the center of gravity G of the whole biped locomotion robot isin the allowable range when the horizontal rotation axes 7H, 8H and 9Hare in such an allowable range. The grounding surface of the footportion 5 is contained in this allowable range. The rotation position ofa servomotor or rotation drive section corresponding to each jointportion is rest and initialized when the adjustment of the center ofgravity is ended.

[0051] It should be noted that in this example, the handle portions 13are attached to the side portions 14 of the fundamental body portion 6.However, the handle portions 13 may be provided as protrusion sections(not shown). Also, it is not necessary that the handle portions 13 areon a same horizontal plane. If the position of the center of gravity islocated on a slant plane passing through the handle portions 13, it ispossible to stabilize the posture of the robot easily. The adjustment ofthe origin by the robot itself is possible by using the handle portionsand the reference surface.

[0052] Various parameters are contained in the walking control. It hasbeen proved that impact relaxation, proper rigidity and the optimizationof mass of a movement body are important physical factors for thewalking control. In the biped locomotion robot of the present invention,the following relations are set.

[0053] (1) The rigidity of the fundamental body portion 6 or therigidity of the fundamental body portion 6 and the object rigidlycoupled to the fundamental body portion 6>the rigidity of the first legportion 3>the rigidity of the second leg portion 4,

[0054] (2) The total mass of all the objects weighting on thefundamental body portion 6>the mass of the first leg portion 3>the massof the second leg portion 4, and

[0055] (3) The condition (1)+the condition (2)

[0056] The rigidities may be defined based on the flexural rigidity orthe torsional rigidity when the both ends of each object are supportedand a load or pressure is applied to a predetermined position or region.It is important that the rigidity of the object coupled to thefundamental body portion 6 and located in a further distance downwardlyfrom the fundamental body portion 6 is lower and smaller in mass. Theconditions (1), (2) and/or (3) facilitate the analysis of the variabledependence and parameter dependence in the directional control. Forexample, when the mass of the foot portion 5 is larger, the movement ofthe foot portion 5 has a large influence on the control of the whole ofsystems. Thus, it is difficult to determine whether the movement of thewhole of systems depends on the pursuit of the servomotor or thecentrifugal movement of the foot portion 5 with a large inertia (inertiamass). However, if the mass of the foot portion 5 is set small, it canbe determined that the movement of the whole of systems depends on thepursuit of the servomotor largely. This depends strongly on the rigidityof each system especially. The first and second links are properly givenwith high rigidities and the rigidities of them are designed to be lowerthan the rigidity of the fundamental body portion.

[0057] When the attachment portions of the handle portion are determinedfor the gravity center to be located in the neighborhood of a horizontalregion containing the handle portions 13, the stability is good when thewhole robot is carried by using the handle portions 13. Especially, whenthe robot is installed on the stiff pillar by using the handle portions13, it is easy to adjust the positions of the foot portions 5 to thehandle portions 13 such that the grounding surfaces of the foot portions5 are parallel to the reference plane of the handle portions 13.

[0058] In case that the arm portions 25 and the head portion 22 areattached freely in swinging to the fundamental body portion 6 with thehighest rigidity or the upper body housing 11 having of a high rigidityand coupled to the fundamental body portion 6 in the robot, the lightweight of the whole system can be realized. The cell battery is insertedbetween the fundamental body portion 6 and the upper body housing 11 anduse efficiency of the space can be improved while keeping the rigidity.

[0059]FIG. 12 shows the body section cover 16 and the carrying typecontrol unit 26. FIG. 13 shows a part of the fundamental body portion 6when an upper portion 26A of the carrying type control unit 26 isremoved and a part of the body section cover 16 is opened. FIG. 14 is aperspective view of the whole of fundamental body portion 6. In FIG. 14,the arrow F shows the front direction. The fundamental body portion 6 isformed of light alloy casting as a unit to have a high rigidity and aproper thickness in the vertical direction. Two positioning holes 41corresponding to the two leg portions are formed in the fundamental bodyportion 6. To position each leg portion, a positioning pin hole 45 isformed. The two leg portions are firmly coupled to the fundamental bodyportion 6 with bolts passing through bolt holes 44 which are formed inthe fundamental body portion 6. A reinforcement rib 49 is formed in across in each of the two positioning holes 41.

[0060]FIGS. 15 and 16 show a structural section 52 of the first jointportion 7. The structural section 52 of the first joint portion 7 has afixation section 52A and a rotation section 52B. The top section of thefixation section 52 a of the structural section 52 is formed to have anouter circular cylinder surface 54. The circular cylinder surface 54 isfit to the positioning hole 41 shown in FIG. 14 coaxially. In case ofthe attachment of the first joint portion 7, the positioning pin 55which stands upwardly from a surface of the fixation section 52 a isinserted in the positioning pin hole 45 of FIG. 14 to determine theposition relation of the structural section 52 and the fundamental bodyportion 6. The structural section 52 and the fundamental body portion 6is coupled firmly in a high rigidity with bolts (not shown) passingthrough bolt hole 56 on the side of the structural section 52 and thebolt holes 44 on the side of the fundamental body portion 6.

[0061] The foot portion 5 is provided apart from the center of gravity Gand is controlled to have the degrees of freedom of multiple axesthrough the first leg portion 3 and the second leg portion 4. Therefore,the movement control of the foot portion 5 in case of the foot risingmovement and the foot grounding movement is more faithfully carried outwith respect to the reference coordinate system which is fixed on thefundamental body portion 6, comparing a case that the first leg portion3 and the second leg portion 4 have higher rigidities than thefundamental body portion 6. Thus, the first joint portion 7 is rotatablewith respect to the fundamental body portion 6 in one axis or two axes.

[0062] In the biped locomotion robot of the present invention, theorigin adjustment can be carried out easily in a high precision.Especially, the rigidity is lower in a portion further distant from themechanical origin. Therefore, the grounding impact can be attenuatedeasily at the portion further distant from the mechanical origin. Thecontrol of the rotation moment in the floating state of the foot portionbecomes easy because of the lower rigidity and the fact that the portionfurther distant from the mechanical origin has a smaller mass. As aresult, the initialization of the control on the grounding of the footportion becomes easy. The handle portions are provided on positions nearthe center of gravity so that the stability is good. When the bipedlocomotion robot is in the stationary condition by fixing the mechanicalorigin using the handle portions, the initialization of the system ofthe robot is carried out. Therefore, the initialization work is simple.

1. A biped locomotion robot comprising: a fundamental body portion; anupper body housing rigidly coupled to said fundamental body portion; twoleg portions movably coupled to said fundamental body portion; a footportion movably coupled to each of said two leg portions; a head portionmovably coupled to said upper body housing; and two arm portions movablycoupled to said upper body housing.
 2. The biped locomotion robotaccording to claim 1, wherein said fundamental body portion functions asa mechanical origin.
 3. The biped locomotion robot according to claim 1or 2, wherein said fundamental body portion further comprises two handleportions provided for attachment portions opposing to each other of saidfundamental body portion.
 4. The biped locomotion robot according toclaim 3, wherein a center of gravity of said biped locomotion robot islocated between vertical planes, each of which passes throughcorresponding ends of said attachment portions of said two handleportions to said fundamental body portion, when said biped locomotionrobot is in an initial state.
 5. The biped locomotion robot according toclaim 3 or 4, wherein each of said two leg portions comprises: a firstlink provided to support said fundamental body portion through a firstjoint portion; and a second link provided to support said first linkthrough a second joint portion.
 6. The biped locomotion robot accordingto claim 5, wherein a horizontal rotation axis of said first jointportion and a horizontal rotation axis of said second joint portion arelocated between vertical planes, each of which passes throughcorresponding ends of said attachment portions of said two handleportions to said fundamental body portion, when said biped locomotionrobot is in an initial state.
 7. The biped locomotion robot according toclaim 5 or 6, wherein said foot portions support said second linksthrough third joint portions, respectively.
 8. The biped locomotionrobot according to claim 7, wherein a horizontal rotation axis of saidthird joint portion is located between vertical planes, each of whichpasses through corresponding ends of said attachment portions of saidtwo handle portions to said fundamental body portion, when said bipedlocomotion robot is in an initial state.
 10. The biped locomotion robotaccording to any of claims 1 or 4, wherein each of said two leg portionscomprises: a first link provided to support said fundamental bodyportion through a first joint portion; and a second link provided tosupport said first link through a second joint portion, and the rigidityof said first link is lower than that of said fundamental body portion,and the rigidity of said second link is lower than that of said firstlink.
 10. The biped locomotion robot according to claim 9, wherein saidfirst joint portion has a vertical rotation axis.
 11. The bipedlocomotion robot according to claim 1 or 10, wherein said upper bodyhousing is coupled to said fundamental body portion to have a gapbetween said upper body housing and said fundamental body portion. 12.The biped locomotion robot according to claim 11, wherein an energysource is arranged in said gap.
 13. The biped locomotion robot accordingto claim 1, further comprising: a control unit provided for a back ofsaid upper body housing.